com.blackypaw.mc.i18n.chat.ChatComponentDeserializer.java Source code

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Here is the source code for com.blackypaw.mc.i18n.chat.ChatComponentDeserializer.java

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/*
 * Copyright (c) 2016, BlackyPaw
 * All rights reserved.
 *
 * This code is licensed under a BSD 3-Clause license. For further license details view the LICENSE file in the root folder of this source tree.
 */

package com.blackypaw.mc.i18n.chat;

import com.google.gson.JsonArray;
import com.google.gson.JsonDeserializationContext;
import com.google.gson.JsonDeserializer;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.JsonParseException;
import com.google.gson.JsonPrimitive;

import java.lang.reflect.Type;

/**
 * This class provides a Gson deserializer that converts JSON formatted chat messages back into
 * chat components.
 *
 * @author BlackyPaw
 * @version 1.0
 */
public class ChatComponentDeserializer implements JsonDeserializer<ChatComponent> {

    @Override
    public ChatComponent deserialize(JsonElement json, Type type, JsonDeserializationContext ctx)
            throws JsonParseException {
        return this.deserializeComponent(json);
    }

    /**
     * Detects the type of the given json element and deserializes its contents into the appropriate
     * component types.
     *
     * @param json The json element to be deserialized
     *
     * @return The deserialized chat component
     */
    private ChatComponent deserializeComponent(JsonElement json) {
        if (json.isJsonPrimitive()) {
            // Only text components can be raw primitives (strings):
            return this.deserializeTextComponent(json);
        } else if (json.isJsonArray()) {
            // Only text components can be json arrays:
            return this.deserializeComponentArray(json.getAsJsonArray());
        } else {
            return this.deserializeTextComponent(json);
        }
    }

    /**
     * Deserializes a JSON formatted component array, e.g. '["Hey, ",{extra:["there!"]}]'
     *
     * @param json The JSON array to be deserialized into a chat component
     *
     * @return The deserialized chat component
     */
    private ChatComponent deserializeComponentArray(JsonArray json) {
        // Each and every element inside a component array is a text component
        // The first element of the array is considered to be the parent component:

        if (json.size() <= 0) {
            return new TextComponent("");
        }

        final TextComponent parent = this.deserializeTextComponent(json.get(0));
        for (int i = 1; i < json.size(); ++i) {
            parent.addChild(this.deserializeTextComponent(json.get(i)));
        }

        return parent;
    }

    /**
     * Creates a text component given its JSON representation. Both the shorthand notation as
     * a raw string as well as the notation as a full-blown JSON object are supported.
     *
     * @param json The JSON element to be deserialized into a text component
     *
     * @return The deserialized TextComponent
     */
    private TextComponent deserializeTextComponent(JsonElement json) {
        final TextComponent component = new TextComponent("");

        if (json.isJsonPrimitive()) {
            JsonPrimitive primitive = json.getAsJsonPrimitive();
            if (primitive.isString()) {
                component.setText(primitive.getAsString());
            }
        } else if (json.isJsonObject()) {
            JsonObject object = json.getAsJsonObject();

            if (object.has("text")) {
                JsonElement textElement = object.get("text");
                if (textElement.isJsonPrimitive()) {
                    JsonPrimitive textPrimitive = textElement.getAsJsonPrimitive();
                    if (textPrimitive.isString()) {
                        component.setText(textPrimitive.getAsString());
                    }
                }
            }

            if (object.has("extra")) {
                JsonElement extraElement = object.get("extra");
                if (extraElement.isJsonArray()) {
                    JsonArray extraArray = extraElement.getAsJsonArray();
                    for (int i = 0; i < extraArray.size(); ++i) {
                        JsonElement fieldElement = extraArray.get(i);
                        component.addChild(this.deserializeComponent(fieldElement));
                    }
                }
            }
        }

        return component;
    }

}